Structure elucidation and antioxidant activity of a novel polysaccharide isolated from Tricholoma matsutake

In this study, structural features of Tricholoma matsutake polysaccharide (TMP-A) were investigated by a combination of infrared (IR) spectra, gas chromatography-mass spectrometry (GC-MS), nuclear magnetic resonance (NMR) spectroscopy. The results indicated that TMP-A had a backbone of 1,4-beta-d-glucopyranose residue which branches at O-6 based on the experimental results. The branches were mainly composed of an (1-->3)-alpha-d-galactopyranose residue, and terminated with alpha-d-xylopyranose residue. The antioxidant activity of TMP-A was evaluated with several biochemical methods, including DPPH(-) radical scavenging, hydrogen peroxide scavenging, superoxide anion radical scavenging. The results indicated that TMP-A showed strong antioxidant. In the in vitro antioxidant assay by MTT method, TMP-A could attenuate PC12 cell damage significantly caused by hydrogen peroxide.